Tag Archives: SDR

Propaganda Shift: The Panmunjom Summit and monitoring the Voice of Korea

Front page of the North Korean newspaper “Rodong” on April 28, 2018. (Source: Mark Fahey)

With North Korea in the global spotlight, I’ve been making every effort to listen to the Voice of Korea on shortwave. Unfortunately, from here on the east coast of North America, conditions have simply not been in my favor.

Fortunately, a couple of SWLing Post and SRAA contributors have had my back.

Yesterday, Richard Langley, uploaded a great VOK recording made with the U Twente WebSDR on April 28 at 13:30 UTC on 13760 kHz. Thank you Richard!

This morning, North Korean propaganda specialist Mark Fahey uploaded the following VOK recording to the archive and included notes and insight:

[The recording is] off 9,730 kHz so a mint shortwave file.

Recorded at the “Behind The Curtain” remote satellite and HF receiving site near Taipei, Taiwan (the site is remotely operated from Freemans Reach in Australia and was specifically established to monitor North Korean radio & television 24×7).

Remote Module #1 prior to sealing.

[Note: Click here to read about Mark’s self-contained deployable remote SDR stations.]

Remote Module #2 fully weather sealed and ready to deploy.

[…]I must say getting a good recording off shortwave is quite a challenge, just going to their satellite circuits far easier!

[T]he reason for the almost hi-fi quality is that I used the real-time audio enhancement and noise reduction techniques I presented at the Winter SWL Fest. The signal in reality was much noisier:

Click here to download an MP3 copy of the off-air recording.

[I] also have long domestic recordings (which is what I have been focusing on rather than VOK).

[…]Of course domestic in Korean – but that has been my main interest/monitoring – what does the regime say to the domestic audience–?

They seem quite serious (I mean genuine) even acknowledging South Korea as a separate place and Moon being the president of this place. The domestic propaganda now not hiding the fact that South Korea is a separate sovereign nation, which is very un-North Korean propaganda!

The news is still kind of breaking in North Korea and the radio reflects that – the reports sound like Friday was yesterday. It takes a long time for North Korean media to report anything, so news from 3 days ago is presented as if it only happened 3 hours ago.

Also since it’s all topical I will include a YouTube link to a Voice Of Korea Documentary (propaganda to our ears of course–!) that has recently been posted to the Arabia Chapter of The Korean Friendship Association:

https://youtu.be/N6xVtKXXn8Y

Click here to watch on YouTube.

Thank you, Mark! Certainly history in the making.

Mark Fahey is my go-to guy for what’s really happening in North Korea, especially with regards to the message the government shares with its people.

Though I haven’t asked him in advance, I’m sure Mark can follow the comments thread of this post and answer your North Korea questions.

Click here to leave a comment/question or follow the comments thread.

If you have a recording of VOK (or any other broadcaster) that you would like to share, consider contributing to the SRAA.

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Turning the Raspberry Pi 3 B+ into a stand-alone SDR

St. Bandon (3B7A): An all-SDR DXpedition

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3B7A Antenna Layout (Source: SunSDR)

Many thanks to SWLing Post contributor, Mike Hansgen (K8RAT), for passing along this press release from SunSDR:

The 3B7A Saint Brandon team is now active from Saint Brandon and we are exited! This is the first major DXpedition that will be using only SDR transcievers in its setup.[…]

SunSDR2 Pro

Using past experience from their successful FT4TA expedition to Tromelin island and FT4JA Juan de Nova island Expedition, the experienced team lead by F5UFX Seb build their St Brandon setup around the SunSDR2 PRO transceiver, the SPE 1.3K-FA amplifier and ModMic attachable boom microphone.

3B7A will have 5 x HF stations on air simultaneously. Each station will have a SunSDR2 PRO with E-Coder hardware controller, an amplifier, and a ModMic. Logging is done using WinTest in network configuration and all stations will be able to operate CW, SSB or RTTY.

All 5 stations will have will have identical configuration from the keyboard to the amplifier. This will keep the operator focused on the pile-up and improve redundancy in case of any equipment failure.[…]

Click here to read the full article at SunSDR.

Note that I believe the January 2018 Bouvet Island (3YØZ) DXpedition would have also been one of the first major ham radio DXpeditions to use SDRs (FlexRadio SDRs). Sadly, due to weather and engine problems, 3Y0Z were not able to activate.

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SDR Console Version 3: A Holy Grail SDR application for the radio archivist

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Encouraged by SWLing Post contributors Guy Atkins and Ivan Cholakov, I recently installed the latest version of SDR Console on my PC.

I had not tried SDR Console in many, many years, but after Guy announced that SDR Console had moved from preview to Beta, I decided it was time to try it once again.

All I can say is: WOW!

As someone who evaluates a number of software defined receivers and who regularly makes off-air audio and spectrum recordings, I’m simply amazed by SDR Console’s versatility.

The recording functionality, as Guy previously stated, is phenomenal–perhaps the best of any SDR application I’ve used to date save, perhaps, that of the Titan SDR Pro (which is proprietary).

Though I still haven’t logged a lot of hours on SDR Console, I can already mention several powerful features that I love:

Virtual receivers

So few SDR applications allow you to run multiple virtual receivers and–especially–make independent recordings from them simultaneously.

When I started writing this post last night, I was listening to and recording the Voice of Greece on virtual receiver #1, Radio Guinea on #2, and WRMI on #3 using the brilliant little AirSpy HF+.

Audio recording options

When you start a recording of an active virtual receiver, a dialog box pops up allowing you to make a custom file title–it pre-populates the date, start time, frequency and mode. This is a simple but time-saving feature as most SDR applications save files according to global application settings–not for each individual recording. With the SDR Console dialog box, I can insert the name of the broadcaster in the file title which makes organizing recordings later a breeze.

Additionally, you can choose between MP3, WAV or WMA file types for each recording. I know of no other SDR app that gives you this flexibility.

Scheduled recordings

I’ve yet to use the scheduler feature, but based on Guy Atkins’ feedback, I know this will be an invaluable resource for collecting off-air recordings while I’m away from home.

So many features to discover…

As both Guy and Ivan have shown us in past posts, SDR Console allows for multiple application “instances”–meaning, you can run two independent SDRs simultaneously. This is a fantastic feature for those of us who make multiple spectrum recordings. Of course, it’s an ideal platform to compare SDR hardware as settings can be easily matched between both units (something very difficult to do when using different SDR applications).

I’ve so much to learn about SDR Console, but I can tell I’ll be spending a great deal of time with the application this year, attempting to learn every nuance.

I took Guy Atkins’ suggestion for new users of SDR Console and downloaded Paul Jones’ (NN4F) PDF manual.

I sent a donation to Simon (G4ELI) last night after having only used SDR Console for a few minutes. SDR Console is totally free, but I’m a firm believer in supporting creators who are doing amazing things! If you use SDR Console, consider sending Simon a donation as well.

I’ve a little free time this morning and plan to set up SDR Console to run my Elad FDM-S2, RTL-SDR dongle, SDR Play RSP1A and RSP2. It’ll be a bit revolutionary to have one SDR application to unite them all!

Post readers: Any other SDR Console fans out there? What are your favorite features?

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Popular SDR-Console V3 Software Moves from Preview to Beta

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Simon Brown, G4ELI’s widely used, free SDR-Console V3 was upgraded from “Preview” to “Beta 1” level today. Many SDR enthusiasts have waited for this next step; even in Preview form, Version 3 has performed nearly as well as a production release in many ways.

I have briefly used SDR-Console (V2 and V3) off and on for a few years, but it wasn’t until acquiring AirSpy HF+ receivers that I took a serious plunge into V3. Now that I’ve gone through its modest learning curve, I like this SDR software quite a bit!

There are many things I enjoy about SDR-Console, not the least is the power and ease of use of the Recording Scheduler, a feature that’s important to medium wave DXers. I’m sure others who like to set up unattended WAV I/Q recordings for later review benefit from this also.

I’ve not found a list of improvements between Preview and Beta 1, but I suspect Simon has made the upgrade because the Preview has shown itself to be quite stable already. He did publish a list of a few known bugs:

External Radio using IF output does not work.
Remote Server using the SDR-IQ has stutter.
Kits are not signed – a code signing certificate has been purchased from Comodo but is not yet available.

Simon indicates that these bugs will be worked on in the next few weeks.

If you use and benefit from SDR-Console software, please considering support the development efforts through a PayPal donation. Links to download the newest Beta 1 version, and/or to donate, can be found here: http://www.sdr-radio.com/Downloads

Here are a couple YouTube videos which show SDR-Console V3 (Preview build) in action:

Guy Atkins is a Sr. Graphic Designer for T-Mobile and lives near Seattle, Washington. He’s a regular contributor to the SWLing Post.

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The AirSpy HF+ R3 bypass modification

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After SWling Post contributor, Guy Atkins, posted the survey results of his excellent Elad FDM-S2 vs AirSpy HF+ weak signal comparison, I received a few questions about the AirSpy HF+ “R3 Bypass” modification Guy mentioned in his post.

Guy has not yet performed the modification on his HF+–neither have I–but he points out that others have noted it: “significantly boosts sensitivity of the HF+ from longwave up to about 15 MHz, without any noted overload issues.”

I reached out to AirSpy president, Youssef Touil, for a little more insight about this modification. Youssef replied:

During the early phases of the design R3 was a place holder for a 0 ohms resistor that allows experimenters to customize the input impedance. For example:

A 300 pF capacitor will naturally filter the LW/MW bands for better performance in the HAM bands

A 10µH inductor would allow the use of electrically short antennas (E-Field probes) for MW and LW

A short (or high value capacitor) would get you the nominal 50 ohms impedance over the entire band, but then it’s the responsibility of the user to make sure his antenna has the right gain at the right band

A custom filter can also be inserted between the SMA and the tuner block if so desired.

Click to enlarge. (Photo source: RTL-S1DR.com)

R3 and the nearby resistors have been intentionally left outside of the RF shield, and their size was picked to be big enough to allow anyone to play with them. You will notice the size difference with the rest of the components.

In general, unless one knows what he’s doing, it’s not recommended to alter a working system. “If it’s working, don’t fix it”. But, we are hobbyists, and not doing so leaves an uncomfortable feeling of something unachieved. Most brands addressing the hobby market leave some tweaks and even label them in the PCB.

The main purpose of the HF+ is the best possible performance on HF at an affordable price. This is to incite HAMs to get started with this wonderful technology while using an SDR that isn’t worse than their existing analog rig.

The MW/LW/VLF crowd may have slightly different requirements, but that can be addressed by shorting a resistor.

Regards,

Youssef Touil

Thank you, Youssef, for replying to my inquiry so quickly and thoroughly.

No doubt, I too will eventually modify R3–it’s very difficult not to experiment, especially when a product was designed with the experimenter in mind.

I really feel like AirSpy has knocked it out of the ballpark with the HF+. For those of us primarily concerned with HF performance, this SDR is very hard to beat–especially at its $199 price point!

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Video: Comparing the SDRplay RSP1A and Airspy HF+ on HF & MW

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Many thanks to SWLing Post contributor, Ivan Cholakov, who shares the following video where he compares the SDRplay RSP1A and the AirSpy HF+ software defined radios on shortwave and mediumwave: